Toxic and Hazardous Waste Management

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Es 314

EnvironmentAl

engineering

presents:

Es 314

EnvironmentAl

engineering

presents:


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TOXIC AND

HAZARDOUS

WASTE

MANAGEMENT


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waste

substances or objects which aredisposed of or are intended to be

disposed of or are required to be

disposed of by the provisions of the law


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kinds of wastes

Solid waste- domestic, commercial and

industrial wastes especially common as co-disposal of wastes

liquid waste-wastes in liquid form


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Classification of Wastes according to their

Properties

bio-degradablenon-biodegradable


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Classification of Wastes according totheir Effects on Human Health and the

EnvironmentHazardous wastesSubstances unsafe to use commercially,industrially, agriculturally, or economicallythat are shipped, transported to or brought

from the country of origin for dumping ordisposal in, or in transit through, any part ofthe territory.


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Non-hazardousSubstances safe to use commercially,industrially, agriculturally, or economicallythat are shipped, transported to or broughtfrom the country of origin for dumping ordisposal in, or in transit through, any part

of the territory


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hazardous-wastemanagement

It is the collection, treatment, and disposal of

waste material that, when improperly handled,can cause substantial harm to human health and

safety or to the environment.


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Hazardous waste

may be as any waste orcombination of wastes that

poses substantial danger to

human beings, plants andanimals.


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Characteristics of a Hazardous

Waste:

Ignitable

CorrosiveReactive

ToxicRadioactive


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Ignitability

Ignitable wastes are capable of causing or

intensifying a fire during routine handling.


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A waste is characteristic for ignitability if it

has any one of the following properties:

a liquid with a flash point less than 140 0F (60 0C);

a solid, capable under standard temperature and

pressure, of causing fire through friction, absorption

of moisture, or spontaneous chemical changes, and

when ignited, burns vigorously and persistently;

an ignitable compressed gas; or,

an oxidizer.


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Corrosivity

Corrosive wastes include highly acidic orhighly alkaline chemicals and those that

are capable of corroding metal.


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A waste has the characteristic of corrosivity ifit has one of the following properties:

an aqueous waste with pH 2 or less, or pH 12.5 orgreater; or,

a liquid that corrodes steel at a rate greater than

6.35mm (0.25 inches) per year.


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ReactivityReactive waste is synonymous with unstable

water. Due to its extreme rate of reaction,

an unstable waste, can create an explosive

condition at any stage of the managementcycle of transport, storage, treatment and

disposal.


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A waste has the characteristic of reactivity if it:

is normally unstable and readily undergoesviolent change without detonating;

reacts violently with water;

forms potentially explosive mixtures with water;

mixes with water to generates toxic gases,vapors or fumes in a quantity sufficient to

present a danger to human health or the

environment;


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is a cyanide or sulfide bearing waste which,

when exposed to pH conditions between 2 and

12.5, can generate toxic gases, vapors or fumes

in a quantity sufficient to present a danger tohuman health or the environment;

is capable of detonation or explosive reaction

if subjected to a strong initiating source orheated under confinement;

is readily capable of detonation or explosive;

or,

is a forbidden explosive or a Class A or Class B

explosive.


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Toxicity

A toxic substance is a poisonoussubstance; it is hazardous.


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Toxicity is determined by the ToxicityCharacteristic Leachate Procedure

(TCLP), a laboratory test that measures

the concentration of the toxic materialthat could leach into ground water if

improperly managed.


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Radioactivity

is defined as the spontaneous breakup ofthe nucleus of an atom. Due to its large

nucleus , it is unstable . An unstable

nucleus breaks up and the atom changesto another one lower in mass.


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Two particular hazardous wastes:

Dioxins- is commonly used to refer to a family of toxic chemicals

that share a similar chemical structure and induce harm through a

similar mechanism. A class of chemical contaminants that are

formed during combustion processes such as waste incineration,

forest fires, and backyard trash burning, as well as during some

industrial processes such as paper pulp bleaching and herbicide

manufacturing. The most toxic chemical in the class is 2,3,7,8-

tetrachlorodibenzo-para-dioxin (TCDD). The highest environmental

concentrations of dioxin are usually found in soil and sediment,with much lower levels found in air and water.


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polychlorinated biphenyl (PCB) is any of the 209configurations oforganochlorides with 2 to 10

chlorine atoms attached to biphenyl, which is a

molecule composed of two benzene rings. Thechemical formula for a PCB is C12H10-xClx. 130 of the

209 different PCB arrangements and orientations

are used commercially.
http://en.wikipedia.org/wiki/Organochloridehttp://en.wikipedia.org/wiki/Chlorinehttp://en.wikipedia.org/wiki/Biphenylhttp://en.wikipedia.org/wiki/Benzene_ringhttp://en.wikipedia.org/wiki/Chemical_formulahttp://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Chlorinehttp://en.wikipedia.org/wiki/Chlorinehttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Chemical_formulahttp://en.wikipedia.org/wiki/Benzene_ringhttp://en.wikipedia.org/wiki/Biphenylhttp://en.wikipedia.org/wiki/Chlorinehttp://en.wikipedia.org/wiki/Organochloride


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PCBs were widely used as dielectric and coolant fluids, forexample in transformers, capacitors, and electric motors.

Due to PCBs' toxicity and classification as a persistent

organic pollutant, PCB production was banned by the

United States Congress in 1979 and by the Stockholm

Convention on Persistent Organic Pollutants in 2001.

Concerns about the toxicity of PCBs are largely based on

compounds within this group that share a structural

similarity and toxic mode of action with dioxin. Toxic effects

such as endocrine disruption and neurotoxicity are alsoassociated with other compounds within the group.
http://en.wikipedia.org/wiki/Dielectrichttp://en.wikipedia.org/wiki/Coolanthttp://en.wikipedia.org/wiki/Transformerhttp://en.wikipedia.org/wiki/Capacitorhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Toxicityhttp://en.wikipedia.org/wiki/Persistent_organic_pollutanthttp://en.wikipedia.org/wiki/Persistent_organic_pollutanthttp://en.wikipedia.org/wiki/Stockholm_Convention_on_Persistent_Organic_Pollutantshttp://en.wikipedia.org/wiki/Stockholm_Convention_on_Persistent_Organic_Pollutantshttp://en.wikipedia.org/wiki/Mode_of_actionhttp://en.wikipedia.org/wiki/Polychlorinated_dibenzodioxinshttp://en.wikipedia.org/wiki/Endocrine_disruptionhttp://en.wikipedia.org/wiki/Neurotoxicityhttp://en.wikipedia.org/wiki/Neurotoxicityhttp://en.wikipedia.org/wiki/Endocrine_disruptionhttp://en.wikipedia.org/wiki/Polychlorinated_dibenzodioxinshttp://en.wikipedia.org/wiki/Mode_of_actionhttp://en.wikipedia.org/wiki/Stockholm_Convention_on_Persistent_Organic_Pollutantshttp://en.wikipedia.org/wiki/Stockholm_Convention_on_Persistent_Organic_Pollutantshttp://en.wikipedia.org/wiki/Persistent_organic_pollutanthttp://en.wikipedia.org/wiki/Persistent_organic_pollutanthttp://en.wikipedia.org/wiki/Toxicityhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Capacitorhttp://en.wikipedia.org/wiki/Transformerhttp://en.wikipedia.org/wiki/Coolanthttp://en.wikipedia.org/wiki/Dielectric


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Sources of Waste

Households

Commerce andIndustries


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Agriculture

Fisheries


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Health carefacilities

Mines and

mineralprocessing cites


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Listed Hazardous Waste:

The F-list(non-specific source wastes).This list identifies wastes from commonmanufacturing and industrial processes, such as

solvents that have been used in cleaning or

degreasing operations. Because the processesproducing these wastes can occur in different

sectors of industry, the F-listed wastes are known as

wastes from non-specific sources.


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The K-list(source-specific wastes).This list includes certain wastes from specific

industries, such as petroleum refining or pesticidemanufacturing. Certain sludges and wastewaters

from treatment and production processes in these

industries are examples of source-specific wastes.


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The P-list and the U-list(discarded commercial chemical products).

These lists include specific commercial chemical

products in an unused form. Some pesticides and

some pharmaceutical products become

hazardous waste when discarded.


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The M-listed Wastes(discarded mercury-containing products).

This list includes certain wastes known to containmercury, such as fluorescent lamps, mercury

switches and the products that house these

switches, and mercury-containing novelties.


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Effects of Waste


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Green House Gases are accumulating in Earthsatmosphere as a result of human activities, causing

global mean surface air temperature and subsurfaceocean temperature to rise.

Rising global temperatures are expected to raise sea

levels and change precipitation and other local climateconditions.

Changing regional climates could alter forests, crop

yields, and water supplies.

This could also affect human health, animals, andmany types of ecosystems.


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Deserts might expand into existing rangelands, andfeatures of some of our national parks might bepermanently altered.

Some countries are expected to become warmer,

although sulfates might limit warming in some areas.

Scientists are unable to determine which parts ofthose countries will become wetter or drier, but

there is likely to be an overall trend toward increased

precipitation and evaporation, more intense

rainstorms, and drier soils.

Whether rainfall increases or decreases cannot be

reliably projected for specific areas.


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Three categories of effects fromsubstances of hazardous waste:

a. A carcinogenic effect is an increase in an

individual's risk of contracting cancer.

b. A mutagenic effect is a permanent change in

the genetic material (DNA), which may be

passed along to later generations.

c. A teratogenic effect is an increased risk that a

developing embryo will have physical defects.


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Effects of Hazardous

Wastes to Human Health

Birth defects and reproductive disorders

Cancer

Respiratory Conditions (e.g. Asthma)

Heart Diseases (e.g. Congenital Heart

Disease)


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Hazardous wastes are acquired by the

body through the following:

Inhalation- we can breathe vapors from hazardous liquids or even

from contaminated water while taking a shower.

Ingestion - we can eat fish, fruits and vegetables, or meat that has

been contaminated through exposure to hazardous substances. Also,

small children often eat soil or household materials that may be

contaminated, such as paint chips containing lead. Probably the mostcommon type of exposure is drinking contaminated water.

Dermal exposure- a substance can come into direct contact with and

be absorbed by our skin.


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Treatment Methods on Handling

Toxic and Hazardous Wastea.) Biological Treatment

Its purpose is to convert dissolved and colloidalpollutants to cell mass, water, and gases. However,

many times cell growth is too small to collect by any

practical method. Microorganisms create an increased

demand for oxygen when they are discharged from a

treatment plant to a body of water. The challenge is to

gather the cells into aggregates by filtration or

sedimentation.


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b.) Chemical Treatment

Is a treatment technology, either employed as thesole treatment to produce or used to reduce that

hazard of a particular waste prior to transport,

incineration, and burial.


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Techniques used in handling hazardous waste using

chemical treatment:

Neutralization

Solutions are neutralized to bring about an

acceptable pH. An acidic solution is added with a base toneutralize it; a basic solution is added with an acid to

neutralize the mixture.

A waste is hazardous at a pH less than 2.00 orgreater than 12.50. the final pH values should be in the

range of6.00 to 8.00 to protect natural biodata.


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Oxidation-Reduction (Redox) ReactionsOxidation is conducted under alkaline conditions

to avoid the generation of cyanide gas. The process is

often referred to as alkaline chlorination. An exampleof this reaction is the chlorine oxidation. The reaction

is carried in two steps.


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The 1st step is that the pH is maintained above 10

and the reaction proceeds in a matterof minute. In this step, it is taken with greater care

to maintain a relatively high pH values

because at lower pH there is a potential for theevolution of highly toxic hydrogen

cyanide gas.

NaCN + 2NaOH + Cl2 = NaCNO + 2NaCl + H2O


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The 2nd step proceeds most rapidly around a pH

of 8.00. higher pH values may be selected toreduce chemical consumption in the following

precipitation steps. Often the second

reaction is not carried out because the CNO is

considered nontoxic by current regulations.

2NaCNO + 5NaOH + 3Cl2 = 6NaCl + CO2 + N2 +NaHCO3 + 2H2O


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Precipitation

A process in which an insoluble product isformed calledprecipitate which is often settled or

removed.


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c.) Physical/Chemical Treatment

It is a treatment to separate hazardous waste fromaqueous solution. The waste is not detoxified but only

concentrated for further treatment or recovery.

h d h dl h d


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Techniques used in handling hazardous waste using

physical/chemical treatment:

Carbon Adsorption

Adsorption is a mass-transfer process in which gas

vapors or chemical solutions are held to a solid by

intermolecular forces.

Example of adsorbents:

activated carbon, molecular sieves, silica gel,

activivated alumina


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Distillation

It is the separation of more volatile materials

from less volatile ones by a process of vaporizationand condensation.

Ion Exchange

In this process metals and ionized organic chemicals

are recovered. Ion exchange can be defined as

reversible exchange of an ion on a solid phase with

an ion of like charge in an aqueous phase. This method

is mostly used in water treatment to remove metals

present in water.


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Electrodialysis

An electrodialysis unit uses a membrane to selectively

retain or transmit specific molecules. The membranes

are thin sheets of ion-exchange resin reinforced by

a synthetic fiber backing. The construction of the unit

is such that anion membranes are altered with cationmembranes in stacks of cells in series. An electric

potential is applied across the membrane to provide

the motive force for ion migration.


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Reverse Osmosis

Osmosis is the spontaneous transport of a solvent

from a dilute solution to a concentrated solutionacross an ideal semipermeable membrane that

Impedes passage of the solute but allows the

solvent to flow.

Solvent ExtractionSolvent extraction is also called as liquid extraction and liquid-

liquid extraction. Contaminants can be removed from a waste

stream using liquid-liquid extraction if the wastewater iscontacted with a solvent having a greater solubility for the target

of contaminants than the wastewater. The contaminants will

tend to migrate from wastewater into the solvent.


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ways to reduce

hazardous waste

A id th U f C i l H h ld Cl


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Avoid the Use of Commercial Household Cleaners

Use Natural Compost as Fertilizer

Avoid the Use of Pesticides

Use Water Based Paints

Avoid Using Toxic Drain Cleaners

Use Natural Alternatives for Floor and Metal Polish

Dispose of any Hazardous Waste Safely

Keep Insects under Control with Natural Means


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The major methods of waste management are:Recyclingthe recovery of materials from

products after they have been used by

consumers.

Compostingan aerobic, biological process

of degradation of biodegradable organic matter.

Sewage treatmenta process of treating raw sewage to


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Sewage treatmenta process of treating raw sewage to

produce a non-toxic liquid effluent which is discharged to

rivers or sea and a semi-solid sludge, which is used as a

soil amendment on land, incinerated or disposed of inland fill.

Incinerationa process of combustion designed to

recover energy and reduce the volume of waste going todisposal.

Landfillthe deposition of waste in a specially

designated area, which in modern sites consists of a pre-

constructed cell lined with an impermeable layer (man-

made or natural) and with controls to minimize emissions.


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Let us be responsible on handling our wastes!

Documents

Toxic and Hazardous Waste Management